Synthesis of Fibrous -Like Stripes ZnO: Ce Nano Structures for NO2 and NH3 Sensing
Zinc oxide and Ce doped nanostructures thin films with different ZnO:Ce ratios (3, 5 and 10) wt% have been prepared by Sol - gel spin coating method at optimum annealing temperature of 550 ÃÂC. The synthesized samples were characterized by X - ray diffraction (XRD) , the spectra of the pure and ZnO: Ce nanostructures correspond to the various planes of a hexagonal ZnO phase, also the crystalline size decreased from about 37nm to 27nm by increasing Ce concentration, atomic force microscopy (AFM) analysis shows that th e surface roughness of the samples increased from 1.14 for pure ZnO to 2.15 nm for 10% doping. FESEM measurements show that the ZnO is spherical shape particles which transfers into fibrous - like stripes embedded within a wrinkled shape with different size depending upon the Ce concentration. This change in the surface shape can improve the NO 2 and NH 3 sensing in the two cases of gas sensing measurements, namely static and dynamic case. It was found that the sensitivity was increase d by using the same operat ing temperature. The dynamic results show that the response and recovery times are improved when the Ce concentration is increased. The optical measurements are shown that the transmittance was decreased with increasing of Ce concentration in zinc oxide.